In conventional speech translation systems, there are techniques for improving accuracy in each portion of processing, such as for improving speech recognition accuracy or for improving translation processing accuracy (see Patent Document 1 and Patent Document 2, for example).    [Patent Document 1] JP 2008-243080A (page 1 and FIG. 1, for example)    [Patent Document 2] JP 2009-140503A (page 1 and FIG. 1, for example)